#include <linux/module.h>
  #include <linux/interrupt.h>

  #include <linux/device.h>

  #include <linux/gfp.h>

  
  /*
   * Device resource management aware IRQ request/free implementation.
   */
  struct irq_devres {
  	unsigned int irq;
  	void *dev_id;
  };
  
  static void devm_irq_release(struct device *dev, void *res)
  {
  	struct irq_devres *this = res;
  
  	free_irq(this->irq, this->dev_id);
  }
  
  static int devm_irq_match(struct device *dev, void *res, void *data)
  {
  	struct irq_devres *this = res, *match = data;
  
  	return this->irq == match->irq && this->dev_id == match->dev_id;
  }
  
  /**

   *	devm_request_threaded_irq - allocate an interrupt line for a managed device

   *	@dev: device to request interrupt for
   *	@irq: Interrupt line to allocate
   *	@handler: Function to be called when the IRQ occurs

   *	@thread_fn: function to be called in a threaded interrupt context. NULL
   *		    for devices which handle everything in @handler

   *	@irqflags: Interrupt type flags
   *	@devname: An ascii name for the claiming device
   *	@dev_id: A cookie passed back to the handler function
   *
   *	Except for the extra @dev argument, this function takes the
   *	same arguments and performs the same function as
   *	request_irq().  IRQs requested with this function will be
   *	automatically freed on driver detach.
   *
   *	If an IRQ allocated with this function needs to be freed

   *	separately, devm_free_irq() must be used.

   */

  int devm_request_threaded_irq(struct device *dev, unsigned int irq,
  			      irq_handler_t handler, irq_handler_t thread_fn,
  			      unsigned long irqflags, const char *devname,
  			      void *dev_id)

  {
  	struct irq_devres *dr;
  	int rc;
  
  	dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
  			  GFP_KERNEL);
  	if (!dr)
  		return -ENOMEM;

  	rc = request_threaded_irq(irq, handler, thread_fn, irqflags, devname,
  				  dev_id);

  	if (rc) {

  		devres_free(dr);

  		return rc;
  	}
  
  	dr->irq = irq;
  	dr->dev_id = dev_id;
  	devres_add(dev, dr);
  
  	return 0;
  }

  EXPORT_SYMBOL(devm_request_threaded_irq);

  
  /**
   *	devm_free_irq - free an interrupt
   *	@dev: device to free interrupt for
   *	@irq: Interrupt line to free
   *	@dev_id: Device identity to free
   *
   *	Except for the extra @dev argument, this function takes the
   *	same arguments and performs the same function as free_irq().
   *	This function instead of free_irq() should be used to manually

   *	free IRQs allocated with devm_request_irq().

   */
  void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
  {
  	struct irq_devres match_data = { irq, dev_id };

  	WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
  			       &match_data));

  	free_irq(irq, dev_id);

  }
  EXPORT_SYMBOL(devm_free_irq);